Concrete block constructions of the prior art are made of individual blocks which are conventionally rectangular, and which generally have one or more cavities or channels through the blocks from their top to bottom. During their use in fabricating structures, a layer of mortar is applied onto a foundation, and a course of closely spaced blocks are laid onto the mortar layer, with additional mortar applied between the contiguous block ends. Another layer of mortar is applied to the top of the first course and additional courses are similarly laid, generally staggering the block ends from course to course.
Preparation of multiple batches of the mortar must be done continuously as the wall is built before the mortar sets, and a degree of skill is required to achieve level courses and a vertical wall. Because of the skill required, and additional time in preparing mortar and applying it to each block, construction costs due to labor can be substantial.
The prior art discloses several specialized blocks that have been developed over the years. A general feature has been provisions formed into the blocks to enable them to be dry-stacked, where the inclusion of a layer of mortar between layers and adjacent blocks is eliminated. However, the appearance of such mortar joints is a desirable feature for aesthetic reasons, and some art incorporates designs into the block to simulate such mortar joints.
All of the blocks described in the prior art incorporate channels, cavities, or holes from the upper to lower surface of each block to allow steel reinforcing bars (rebar) to be placed vertically inside the holes, extending through several layers so that when combined with cement, concrete, or grout, superior strength properties for the assembled wall of structure result.
However, in the practice of the art, vertically oriented rebar that has been previously set in a concrete footer or foundation, or has been set in the grout previously poured into a lower layer of blocks requires the lifting of each masonry block to a significant height, above the top of the rebar, to set each in place. In the extreme, each layer of masonry block is lifted to the height of the highest, final layer of blocks, before it is positioned at its own final height, which except for the final layer will be at a lower elevation. The repetitive motions of lifting of the many blocks that comprise a completed wall requires exertion and consumes time from the worker, and introduces fatigue, physical strain, and a risk of injury. None of the prior art adequately addresses this problem.
Thus for example, in U.S. Pat. No. 4,031,678 Schuring discloses an interlocking building block construction comprising an overlapping masonry block having opposite sides, stepped opposite upper and lower longitudinal faces, and stepped opposite vertical end faces. There are spaced tapered recesses with flat bottom surfaces that are located on the upper longitudinal face, and correspondingly shaped lugs that are formed in the lower longitudinal face. There are two enlarged rectangular openings extending entirely through the block located in the central area of the upper and lower faces between the vertical end faces. Small apertures are formed in and adjacent to the lugs for receiving pins for interlocking adjacent blocks. Header blocks, pilaster blocks, partition blocks and filler blocks are provided for interlocking assembly with the interlocking building blocks to build walls of a building without the use of grout or cement.
In U.S. Pat. No. 4,075,808 Pearlman discloses a masonry block having vertically and horizontally offset front and rear faces which form a tongue and groove interlocking feature. The masonry blocks also have bed-to-bed face passages and header-to-header channels to allow mortar to be poured into the masonry element to rigidly hold the masonry block in place. No special importance is placed on the outward appearance of the front face of a structure made with these masonry blocks.
In U.S. Pat. No. 4,514,949 Crespo discloses a wall comprising layers of longitudinally aligned blocks, the blocks having approximately parallel front and back faces connected by transverse webs defining chambers between the webs that are open at the top and bottom. The webs and end faces of each block include depressions in the tops, machined to a specific depth in relation to the height of the block. The upper face of the webs are formed with longitudinally aligned V-shaped grooves which are accurately positioned at a uniform distance from the front faces of the blocks, and steel rebar is fitted in the grooves and extending longitudinally and horizontally from one block to the next to provide longitudinal alignment of the blocks in each row.
In U.S. Pat. No. 5,003,746 Wilston discloses a wall assembly comprising repeating building blocks with vertical channels or holes. Each block is generally rectilinear with the exception of two end walls having round circumferential male and female mating surfaces, respectively. Each circumferential male and female mating surface has a radial dimension almost equal to the width of the block, where each end wall being rotatively engageable with an arcuate mating end wall of an adjacent block of the assembly at any desired angle of rotation within a limited range of arc. The vertical channels or holes comprise means for receiving vertical aligned steel rebar, each hole being aligned with a hole of a block of an adjacent row stacked above and below it.
In U.S. Pat. No. 5,024,035 Hanson discloses a mortarless, lightweight block and walls formed therefrom. The block is generally rectangular and comprises side walls, end walls, and an interior wall which divides the interior of the block into two vertical channels or passages through the block. In certain blocks, parts of the end and interior walls are removed to form horizontal channels through the blocks. The blocks are provided with projections and recesses having rectangular cross sections by which means they may be interlocked together to form walls. In such a wall, the vertical passages and horizontal channels may receive reinforcing steel bars to impart added strength and load bearing properties to the wall.
In U.S. Pat. No. 5,685,119 Zschoppe sets forth shaped bricks joined in a dry construction system. Each brick has a first bearing surface which is provided with a groove formed laterally with a lateral recess, and a second bearing surface which is provided with a key formed laterally with a lateral projection. The projection and the recess are complementary and positioned such that the projection on a first brick is engaged with the recess of a second brick. When stacked, the bricks form chases extending perpendicular to the bearing surfaces and include a central channel and semi tubular channels at opposing end faces. The channels so formed may be used for insertion of steel rebar.
In U.S. Pat. No. 5,715,635 Sherwood discloses a masonry block that includes a pair of mounting strips projecting outwardly from the block supporting faces, each of the strips having an outer planar surface recessed inwardly from the adjacent parallel supporting faces of the block a predetermined amount. The effect, when a plurality of the blocks are assembled, is the mounting strips give the finished wall the appearance of a clay brick wall with mortar joints. Each block includes vertically aligned closed channels suitable for containing steel rebar and grout for strength.
In U.S. Pat. No. 5,729,943 Cambiuzzi discloses a block comprising a transverse groove in each end face, and an opening extending from the first to the second bearing face in which a longitudinal groove is also provided. The block is further provided with reference and positioning structures comprising a pair of longitudinal seats on the bearing face, and a pair of projections each divided into three projection portions on the second bearing face. The apertures and the grooves in the blocks form a grid of intersecting vertical and horizontal channels in which binder or grout is poured and solidifies. These channels may incorporate steel rebar for enhanced strength.
In U.S. Pat. No. 5,802,797 Storer-Folt discloses a masonry system in which specially shaped bricks are dry-stacked and subsequently bonded by pouring mortar or grout into apertures in the brick to flow through the stacked structure to surround the individual brick leaving the front and rear faces exposed. The brick have alignment projections extending from the bottom bed faces which register with alignment grooves in the top bed faces of the lower brick to align the upper brick prior to bonding. The projections and grooves define a recess to admit mortar between adjacent brick faces. The brick also have recesses in the header faces to admit mortar between adjacent header faces. The front faces of the brick are contoured to create the appearance of mortar joints when the brick are stacked. As with other designs, the brick includes rectangular or oval vertical channels to admit inclusion of steel rebar and grout for strength.
In U.S. Pat. No. 6,588,168 Walters discloses a block shaped in the general form of a rectangle. There is a single channel portion of uniform depth extending along the entire length dimension of the block, which channel has an open portion coincident with the top portion. To accommodate vertically placed steel rebar, the channel includes at least one, and preferably two holes on its floor portion, which have a centerline coincident with the height dimension of the block and which pass through to the exterior of the block through the flat bottom portion.
In U.S. Pat. No. 6,962,028 Banova discloses a masonry block comprising contoured headers, a contoured front face, a back face, a contoured lower base and an upper base. The masonry block has a plurality of holes extending from the lower base to the upper base to accommodate vertical steel rebar and grout for enhanced strength. The contoured headers couple to the headers of other masonry blocks and the contoured lower base couples to the upper base of the other masonry blocks so that an outward face of a portion of a wall assembled with the masonry blocks has mortar-like vertical and horizontal gaps.
There persists in the prior art a continuing need for improvements in construction block systems to permit more rapid assembly of the blocks. There is a need to avoid the incorporation of mortar joints between the bricks with its attendant cost in time, labor, and material, but to retain the aesthetically pleasing appearance of mortared joints. On the other hand the need for constructs of enhanced structural strength and integrity persists.
The prior art provides for vertical and horizontal channels so that strength properties derived from the incorporation of steel rebar and grout are obtained. However, in every case where the vertically positioned rebar has already been set in a concrete foundation, it is necessary to lift each masonry block so that it passes over the top end of the rebar. This additional effort is obtained entirely through manual labor incurred with the placement of each masonry block, and the cumulative effect is a significant cost in time and labor.
Therefore, there is a continuing need for improvements in construction block systems to permit lower cost and more rapid structure assembly from the blocks, while still permitting the introduction of reinforcing material into all or some of the blocks. The present invention provides a block useful in the rapid construction of various structures, with structural strength properties derived from the incorporation of steel rebar and grout reinforcing, and the aesthetically pleasing appearance of mortared joints. The features and advantages of the blocks and constructs of this invention will become apparent to one of ordinary skill.